The anticoagulant activity of heparin can be destroyed by an enzyme, heparinase which is extracted from Flavobacterium heparinum grown on heparin as sole source of carbon. The enzyme can be used to neutralize heparin in plasma samples, making possible the performance of accurate coagulation assays which would otherwise be impossible. The purpose of the proposed research is to develop improved methods for the production and purification of heparinase, so that it can be made available to all diagnostic coagulation laboratories.